Disclosed herein is a process comprising selecting a printing system; selecting an ink composition having ink properties that match the printing system; depositing the ink composition onto a substrate to form an image, to form deposited features, or to form a combination thereof; optionally, heating the deposited features to form conductive features on the substrate; and performing a post-printing treatment after depositing the ink composition.
Xerox Corporation has invented a nanosilver particle which is stabilized by an organoamine. U.S. Pat. No. 8,765,025, which is hereby incorporated by reference herein in its entirety, describes a metal nanoparticle composition that includes an organic-stabilized metal nanoparticle and a solvent in which the solvent selected has the following Hansen solubility parameters: a dispersion parameter of about 16 MPa0.5, or more, and a sum of a polarity parameter and a hydrogen bonding parameter of about 8.0 MPa0.5 or less. U.S. Pat. No. 7,270,694, which is hereby incorporated by reference herein in its entirety, describes a process for preparing stabilized silver nanoparticles comprising reacting a silver compound with a reducing agent comprising a hydrazine compound by incrementally adding the silver compound to a first mixture comprising the reducing agent, a stabilizer comprising an organoamine, and a solvent.
U.S. patent application Ser. No. 13/866,704, which is hereby incorporated by reference herein in its entirety, describes stabilized metal-containing nanoparticles prepared by a first method comprising reacting a silver compound with a reducing agent comprising a hydrazine compound by incrementally adding the silver compound to a first mixture comprising the reducing agent, a stabilizer comprising an organoamine, and a solvent. U.S. patent application Ser. No. 14/188,284, which is hereby incorporated by reference herein in its entirety, describes conductive inks having a high silver content for gravure and flexographic printing and methods for producing such conductive inks.
Xerox Corporation has developed flexographic and gravure inks based on silver nanoparticle technology. U.S. patent application Ser. No. 14/594,746, which is hereby incorporated by reference herein in its entirety, describes in the Abstract thereof a nanosilver ink composition including silver nanoparticles; polystyrene; and an ink vehicle. A process for preparing a nanosilver ink composition is described comprising combining silver nanoparticles; polystyrene; and an ink vehicle. A process for forming conductive features on a substrate using flexographic and gravure printing processes is described comprising providing a nanosilver ink composition comprising silver nanoparticles; polystyrene; and an ink vehicle; depositing the nanosilver ink composition onto a substrate to form deposited features; and heating the deposited features on the substrate to form conductive features on the substrate.
U.S. patent application Ser. No. 14/573,191, which is hereby incorporated by reference herein in its entirety, describes in the Abstract thereof a nanosilver ink composition including silver nanoparticles; a clay dispersion; and an ink vehicle. A process for forming conductive features on a substrate is described including providing a nanosilver ink composition comprising silver nanoparticles; a clay dispersion; and an ink vehicle; depositing the nanosilver ink composition onto a substrate to form deposited features; and heating the deposited features on the substrate to form conductive features on the substrate. Inks have been successfully formulated in non-polar solvents such as decalin and bicyclohexyl and successfully printed using inkjet printing technologies. As printed electronics matures and moves to higher volume production, it is desirable to have inks that can be used in offset printing technologies such as flexography and gravure. Offset printing technologies provide established printing processes and equipment. FIG. 1 shows a schematic diagram of a flexographic printing process. Flexographic printing processes generally comprise the following steps: a) anilox roller 100 having metered anilox cells 112 picks up ink from the ink pan 114; b) doctor blade 116 scrapes off excess ink; c) ink is then deposited on to the flexo-plate 118; d) flexo plate 118 and plate cylinder 120 transfer features onto the substrate (material web) 122 shown exiting impression cylinder 124.
A gravure printing process is very similar to flexography except that it does not have an anilox roller and the image is engraved onto a metal cylinder. This makes gravure more expensive than flexo and high volume printing. One of the main advantages of gravure over flexo is the ability to consistently make high quality prints. FIG. 2 shows a schematic diagram of a gravure printing process. Gravure processes generally comprise the following steps: a) plate 200 comprising plate cylinder 212 picks up ink 214 from the ink pan; b) doctor blade 216 scrapes off excess ink; c) ink is then transferred from the plate cylinder 212 to the substrate (paper) 218 shown exiting impression cylinder 220 having printed image 222 printed thereon.
Gravure and flexographic processes provide a potentially efficient way to manufacture a number of conductive components at a lower cost than that of other printing applications. However, such processes require different processing parameters than conventional graphics printing, particularly for electronics applications.
A need remains for improved printing processes, in embodiments, for improved gravure and flexographic printing processes. Further, a need remains for an improved printing process for printed graphics and printed electronics applications. Further, a need remains for a reliable gravure printing process that can be used for printed electronics applications.
The appropriate components and process aspects of each of the foregoing U.S. Patents and Patent Publications may be selected for the present disclosure in embodiments thereof. Further, throughout this application, various publications, patents, and published patent applications are referred to by an identifying citation. The disclosures of the publications, patents, and published patent applications referenced in this application are hereby incorporated by reference into the present disclosure to more fully describe the state of the art to which this invention pertains.